I started my apprenticeship in 1961 with a now distant airline that had a Bristol Hercules overhaul line which at that time was all for third parties. I spent a lot of time in the various sections comprising the line and deveoped a great deal of respect for the designers. We also had a low rate P&W R2800 overhaul line but I think I preferred the Hercules as a machine. Assembly of the Hercules was very simple and two experienced mechanics and an apprentice churned out an engine to the test cell every 10 working days without raising a sweat. Timing of the sleeve drive gears was a piece of cake. As far as I can recall we never had a serious failure and all engines ran to their overhaul life on wing. By this time Bristol seem to have resolved any sleeve lubrication issues.
In contrast there were some nasty, expensive failures with the R2800's eg. master rod cylinders blowing off, crankshaft failure.
One particular beauty of the Hercules was the elimination of lockwire inside the crankcase. Everything was locked by tabwashers or split pins. In contrast the R2800 used lockwire everywhere and one had to be very careful not to overtwist the wire which fatigued it and could result in an premature engine removal due to "lockwire in the filters". I recall a senior apprentice being very downcast after he had spent 1 or 2 days lockwiring all the valve gear in a front case only to have it all rejected by the inspector for overtwisting (no more than 5 twists per half inch rings a bell).